In recent years, public interest in odor in daily life has grown, and stationary-type deodorizing products, spray-type deodorizing products, and various other deodorizing products (e.g., wallpaper, curtain, carpet, mat, sofa, filter, and clothes) that are provided with a deodorizing effect have been put on the market in order to deal with a demand for a reduction in an unpleasant odor or an offensive odor. Examples of the unpleasant odor or the offensive odor include a putrid odor (e.g., emitted from garbage), a human or animal excretion odor, sweaty odor, and aging odor, an aldehyde emitted from furniture and home appliances, a cigarette odor, and the like. Since an odor in daily life is normally a complex odor including a plurality of components, a combination of deodorizing components has been proposed so as to deodorize such a complex odor.
Activated carbon has been widely used as a deodorant. Since activated carbon is characterized by physical adsorption, it is difficult to use activated carbon as a general-purpose deodorant in various applications. Physical adsorption has a drawback in that a gas other than a gas that emits an offensive odor is continuously adsorbed in an open space irrespective of the type of gas component, and the adsorption capacity is immediately saturated. Moreover, when the adsorption capacity has been saturated, or the ambient temperature has increased, the adsorbed gas is released, and emits an offensive odor. Therefore, activated carbon can only be used for a product that can be replaced (exchanged). Since activated carbon has a black color, it is difficult to produce a white or chromatic deodorizing, product using activated carbon. In order to deal with the above problem, a deodorant that utilizes chemical adsorption and has a white or light color has been developed.
For example, Patent Document 1 discloses a deodorant that consists of a fine zinc oxide having a specific surface area of 40 to 100 m2/g, a hydrogen sulfide deodorizing capacity of 3.0 mmol/g, and a primary particle size of 0.2 μm or less, and that is suitable deodorizing sulfur-based gas. Patent Document 2 discloses a deodorant that consists of particles in which zinc oxide and either or both of aluminum oxide and silicon oxide are closely bonded, and that is suitable for deodorizing an ammonia-based gas, an amine-based gas, or a sulfur-based gas. Patent Document 3 discloses a deodorant composition that includes a deodorant in which a compound having a primary amino group is supported on an organic or inorganic carrier (support), and a deodorant including aluminum silicate, and is suitable for deodorizing an aldehyde gas or a basic gas.
Patent Document 4 discloses an aluminum silicate having a BET specific surface area of 450 to 600 m2/g and a pore volume of 0.6 to 1.2 mL/g, and describes that this compound is a basic substance adsorbent. Patent Document 5 discloses a deodorant consisting of a layered zirconium phosphate represented by Zr1-xHfxHx(PO4)6·nH2O.
Patent Document 6 discloses a deodorant that includes a metal complex of a hydrazide compound as an effective component, and is suitable for deodorizing an aldehyde gas or an acidic gas. Patent Document 7 discloses a deodorant for an aldehyde gas that includes a mixture including an aminoguanidine salt in which a pH becomes 1 to 7 when dissolved in purified water, and at least one compound selected from a silicate compound in which a pH becomes 2 to 8 when dispersed in purified water, a tetravalent metal phosphate compound in which a pH becomes 2 to 8 when dispersed in purified water, a zeolite in which a pH becomes 2 to 8 when dispersed in purified water, and a silica gel in which a pH becomes 2 to 8 when dispersed in purified water, wherein a pH of an aqueous suspension including the mixture becomes 1 to 7.
However, these chemical adsorption-type deodorants differ as to the reaction mechanism, and one deodorant can normally adsorb only one type of offensive odor. Therefore, it is necessary to use a plurality of deodorants in combination in order to deal with a complex odor.
For example, Patent Document 8 discloses a deodorant composition that includes an aldehyde gas deodorant in which at least one compound selected from the group consisting of succinic acid dihydrazide, carbohydrazide, and oxalic acid dihydrazide is supported on at least one compound selected from the group consisting of a silicate compound and a tetravalent metal phosphate, and at least one deodorant selected from the group consisting of a sulfur-based gas deodorant, a basic gas deodorant, and an organic acidic gas deodorant, and further a deodorant composition that includes an aldehyde gas deodorant in which at least one compound selected from the group consisting of saccinic acid dihydrazide, carbohydrazide, and oxalic acid dihydrazide is supported on a mixture including at least one compound selected from the group consisting of an aluminum silicate, a zeolite, and a tetravalent metal phosphate, and magnesium silicate, and at least one deodorant selected from the group consisting of a sulfur-based gas deodorant, a basic gas deodorant, and an organic acidic gas deodorant.
Patent Document 9 discloses an adsorbent composition that includes silicon dioxide, a water-insoluble phosphate of a tetravalent metal, and a hydroxide of a divalent metal, and is suitable for deodorizing an acidic gas and a basic gas.
Patent Document 10 discloses a deodorant for a film that includes a porous inorganic substance, an amine compound, and a metal oxide, and is suitable for deodorizing an aldehyde gas, a basic gas, and a sulfur-based gas, wherein the average particle size of at least one component is 5 to 30 μm.
Patent Document 11 discloses a deodorizing carpet having a nonwoven fabric onto which a deodorant that includes a porous inorganic substance, an amine compound, and a metal oxide is sprayed, and a skin layer consisting of pile yarns and a ground fabric.